Realme - Defective Phone

Relme * phone purchased on Feb.**,****. on sep. ** phone stop working. give it to service center on Sep.**, return by service center on Sep.**. but error was not resolved.against submitted to service center and this time after one week they return stating error is resolved. But after * days same issue occurs submitted to service center at surat on ********. but till date issue not resolved. As per customer care information any complain must be resolved with in * days in my case more than ** days already passed but company unable to provide solution.